Energy stored in a capacitor over a cycle, when excited by an $$a.c.$$ source is

A $$10$$ $$V$$ battery with an internal resistance of $$1\,\Omega $$ is connected across a nonlinear load whose $$V-1$$ characteristic is given by $$7{\rm I} = {V^2} + 2V.$$ The current delivered by the battery is ............... $$A.$$

The value of $$E$$ and $${\rm I}$$ for the circuit shown in Figure, are ..... $$V$$ and ...... $$A.$$

The voltage and current waveforms for an element are shown in Figure. The circuit element is .......... and its value is .........